The objectives of this proposal are to determine the heterogeneous forms in which the gonadotropins, luteinizing hormone (hLH) and follicle stimulating hormone (hFSH) circulate and are excreted. By conjunction of radioimmunoassay with the methods devised for the determination of in vitro biological activity for hLH in unaltered serum, biologic to immunologic (B/I) ratios will be determined in serum. The serum will be collected from normal individuals, whose hormone production has been stimulated by luteinizing hormone releasing hormone (LHRH) or suppressed with steroids, and from patients. In conditions where discrepancies between the bio and immunologic potency are noted, further studies will be undertaken to more completely characterize the hormonal forms. To identify the biologically active heterogeneous hFSH forms in serum, in a manner similar to hLH, it is our intention to develop sensitive in vitro bioassays. Cyclic adenyl monophosphate (cAMP) and androgen binding protein (ABP) production in cultured rat. Sertoli cells will be utilized as parameters of biological action. In order to initiate studies of gonadotropin metabolism in vivo, two approaches will be utilized. The first is to develop region-specific radioimmunoassays to sequence specific disulfide cleaved subunits or fragments. These immunoassays can then be used to probe for forms or metabolic products of hormones which cannot be detected by highly conformation-specific antisera prepared against native hormones or subunits. The second approach is to adapt the in vitro bioassays to the study of biologically active hormonal forms in urine. In order to accomplish this, factors causing toxicity to cells must be eliminated.